Trailer connector

ABSTRACT

A multiconductor electrical connector socket comprising a conducting flange, having a permanently affixed ground conductor and plug receiving chamber, and a detachable molded insulating base containing circuit breakers. The detachable base has permanently affixed circuit breakers, conducting pins and buss strips in order to minimize the number of manual connection terminals. The connector is constructed so that when the flange and base are joined, an enclosure is formed, protecting the circuit breakers from damaging external forces.

United States Patentv Martin Bl Brandt Inventors Needham;

Kent J. Batcheller, Westwood; Francis Donald Kircholl, Waban, all of,Mass. App]. No. 23,219 Filed Mar. 27, 1970 Patented Aug. 24, 1971Assignee Joseph Pollak Corporation Boston, Mas.

TRAILER CONNECTOR 6 Claims, 6 Drawing Figs.

U.S. Cl 317/99, 337/113, 337/338 Int. Cl 110111 61/01 Field oISearch337/113,

l87,188,189,l97, 198,199, 338; 317/99; 200/51 R [56] References CitedUNITED STATES PATENTS 3,315,131 4/1967 Klimaket al 317/99 3,270,2498/1966 Unsworth 337/113 (X) 3,059,073 10/1962 French,.lr. .Q 200/51R(X)Primary Examiner-Hemard A. Gilheany Assistant Examiner-Dewitt M. MorganAttorney-Kenway, Jenney & Hildreth ABSTRACT: A multiconductor electricalconnector socketcomprising a conducting flange, having a permanentlyaffixed ground conductor and plug receiving chamber, and a detachablemolded insulating base containing circuit breakers. The detachable basehas permanently affixed circuit breakers, conducting pins and bussstrips in order to minimize the number of manual connection terminals.The connector is constructed so that when the flange and base arejoined, an

enclosure is formed, protecting the circuit breakers from damagingexternal forces.

PATENTEH M1524 l9?! SHEET 10F 2 FIG.

FIG.3

NT RTI FRAN INVENTORS KE J BATCHELLER MA 8. BRANDT o KIRCHOFF 7 5mm,,

ATTORNEYS FIG. 4

FIG. 5

mvsmons KENT .1. BATCHELLER MARTIN B. BRANDT FRANCIS o. KIRCHOFF BY W,M

ATTORNEYS TRAILER CONNECTOR This invention relates generally tomulticonductor electrical connectors used to connect electrical deviceswith a power source. More specifically, the invention relates toimprovements in multiconductor electrical connector sockets forautomotive trailers where such sockets have integrated protectivecircuit elements. The electrical connectors are used to energize thelighting system and other electrical devices of a trailer from the powersource of a vehicle such as an automotive tractor. I

When an automotive vehicle is hitched to a trailer, power or, insomecases, electrical control switches and relays, must be interconnectedwith electrical equipment in the trailer. The interconnection isnormally achieved by means of a multiple contact cable plug and'socket.Usually, the vehicle plug is a female type which is connected throughswitches or controls to the power source by a multiconductor cable. Themale socket is mounted on the wall of the trailer facing the vehicle ortractor and has conducting pins disposed within a plug receivingchamber. Each electrical device is connected to its appropriate socketterminal which, in turn, is connected to a conducting pin. To assurethat each individualcircuitof the trailer is properly connected with thepower source when the male socket and female plug are joined, the socketand plug are provided with a key or other indexing means such as anoutsized conducting pin.

In order to avoid damage to the electrical devices and the power source,protective circuit elements are usually employed in each circuit. Theseprotective elements are most commonly circuit breakers or fuses whichare inserted in each circuit. Heretofore; a plurality of individuallyremovable circuit breakers have been used. However, there are normallyquite a few conducting pins, each with relatedterminals and circuitbreakers. When each circuit breaker is individually removable, thenumber of manual electrical connections is large. Furthermore, it isoften difficult to ascertain precisely which of several circuit breakers'may be faulty or need replacement and considerable time may be neededtodetermine and correct the fault. The present invention contemplates moreconvenient, more efficient, and cheaper servicing by making it possibleto replace all circuit breakers in a single operation rather than havingto check. each individual circuit breaker. Although the cost of parts isobviously greater, the time spent in diagnosing faults and replacingcircuitelements where a large number of manual connections must bedisconnected and then reconnected is more costly than the parts.

The invention is embodied in animproved electrical connector sockethaving a plurality of permanently affixed circuit breakers contained ina removable, integral unit. An unskilled operator is thus enabled toeasily service and replace the base plate of the connector unitcontaining circuit breakers by making a minimum of manual electricalconnections.

The socket of the invention also safeguards the protective circuitelements from damage caused by weather or accidental contact with otherobjects.

Furthermore, a permanently affixed ground conducting pin in the socketassures an improved ground contact and. further reduces the number ofmanual electrical connections.

Other features of this invention include a better and stronger guidingmeans for a female plug, permanently affixed bus strips which eliminatemanual electrical connections and which reduce the danger of shortcircuiting from bus strip flexing', and a more durable construction.

In the drawings:

FIG. 1 is a plan view of a connector flange,

FIG. 2 is a side view of the flange of FIG. 1 with a fragmentarysectional view revealing-a ground pin,

FIG. 3 is a rear plan view of the connector flange of FIG. 1 and aninsulated base therefor,

FIG. 4 is a side view, partly in'section of the insulating base andflange of FIG. 3,

'FIG. 5 is a side view of the insulating base; and

FIG. 6 is a front sectional elevation of the insulating base.

The invention is particularly adapted to be used in an automotivetrailer, although it could easily be employed wherever severalelectrical devices are protectively connected to a power source. Whilethe specific connector socket shown and described is a 7-conductorelectrical connector adapted to receive a conventional automotivetractor cable, the number of conductors may be more or less than seven,as dictated by the application of the connector.

In FIGs. l and 2, there may be seen a housing member which includes adie cast flange 10 having a hinged cover 12. A raised tubular receivingchamber 14 and a circular ridge l5 and bosses 16 are formed on the backof theflange 10. A permanently afflxed ground conducting pin l8extendsfrom the back wall and within the chamber 14. The wall of the chamber 14defines the inner boundary of a circular recess 20 on the back of saidflange 10.

.A molded ,base 22, of insulating material having a raised central areais shown in FIGS. 3 and 4. Radially arrayed in deep recesses in the backof the base 22 by rivets or other suitable fasteners are a plurality ofconducting bus strips 24. The bus strips 24 connect a plurality'ofconducting pin bases 25 individually to a like plurality of rivets 27disposed in a circular array and'passing through the base 22. On theopposite or front surface ofthe base 22, a raised inner base wall 28 andouter base wall 30 are formed. A plurality of conducting pins 32 andbimetallic circuit breakers 34 are also disposed on the inner face ofsaid base 22. The conducting pins 32 are arrayed placed in the housingmember and the two parts are joined together by means of screws 36passing through holes 38 in the base 22 into threaded holes 40 in thebosses 16 or by-other similar means, the conducting pins 32 extendinto'the plug receiving chamber 14, and the circuit breakers 34 will'becontained withinthe recess 20-which is completely enclosed by the flange10, the ridgelS, the outer base wall'30, the base 22, the inner basewall 28, and the receiving chamber wall 14.

The flange 10 is preferably constructed of a strong, lightweight,electrically conducting material such as aluminum. The. flange is of agenerally oval shape to provide areas in which holes 44 are bored topermit the'flange 10 to be secured to the wall of a trailer. The flange10 may be die cast with recesses 48 to save material and to lighten theweight of the connector socket without substantially weakening itsstructure. A hinge pin 50 passes through the cover 12 and small openings49 in the flange cover brackets 51 to hold the cover 12 in place. Acoiled spring 52wound around the hinge pin 50 may serve to maintain thecover 12 in a normally closed position.

The cover 12 has a tongue 53 formed on its inner surface which is of ashape and orientation with respect to the cover 12 that, when the coveris lifted to-accommodate a cable or plug, the plug is held in place bythe spring-loaded pressure of the tongue. An arcuate surface 54-isformed on the end of the tongue 53 and it conforms to the perimeter ofthe cable or plug-to hold the cover inits raised position and to holdthe cablesecurely in place in the socket.

Also, the cover has a reentrant inner edge formed by two ridgesto fitover a ridge around the socket opening of the flange 10 to prevent theentry of dirt, water, and other unwanted matter into the plug receivingchamber.

The design of the assembled socket elements is such that, uponinstallation in a suitable opening in the trailer wall, only. thedie'cast flange l0 and ridge 15 arein contact with the trailer wall. Thebase 22, made of more fragile nonconducting material is thus protectedfrom the shock and strainthat is encountered in normal use where thetrailer is subjected to travel over rough roads or terrain. Thereceiving chamber 14 may, if

tion as by staking to a segment 19 formed as a portion of the bottomwall of the receiving chamber 14. The segment 19 defines the depth ofthe plug receiving chamber and aligns the pin 18 parallel to thereceiving chamber wall 14 while assuring a good electrical connectionwithout need for a manual connection terminal. Since it is not a part ofthe removable insulating base 22, it is not necessary to put in a newground pin when the base 22 is replaced, resulting in more efficiencyand less cost for such replacement.

' The molded insulating base 22 is made of a strong, 42 insulating base22 and the die cast flange nonconducting, waterproof material, such asBakelite. The conducting pins 32 are disposed within and parallel to theinner base wall 28 which is larger than, but of the same shape as, thereceiving chamber 14. When the insulating base 22 and the die castflange 10 are fitted together, the wall of the receiving chamber 14provides guiding means for the base 22. Positive alignment andorientation are readily achieved with the aid of indexing means such asthe previously mentioned out-of-round areas formed on the inner basewall 28 and receiving chamber wall 14, respectively. The conducting pins32 are so disposed that when the two parts are properly joined together,the conducting pins do not interfere with the ground pin 18, and the pinholding segment 19 will be substantially flush against the base Eachconducting pin 32 has an end of reduced diameter 25 anchored in anopening in the base 22 and riveted to one end of a bus strip 24 which isset in a recessed area on the back of the base. The bus strips 24 arebent to conform to the surface of the base 22 and are deeply recessedalong their entire lengths, eliminating any chance of short-circuitingbetween strips or between connector terminals and strips. The structurealso protects against short-circuiting by foreign objects coming incontact with the back of the connector. An end of each bus strip 24 isriveted through the base and the opposite end of each rivet fonns acontact point for the nonsecured end of a bimetallic circuit breaker 34,the secured end of each circuit breaker being riveted to a terminal intowhich a, screw 26 is threaded as shown in FIG. 4. Each of the bus strips24 is pro tected from contact with another strip by being substantiallyrecessed into the insulating base. Furthermore, since the bus strips arepermanently affixed, they are not subject to wear and potential breakagefrom the flexing which accompanies the replacement of individualbreakers as they are found in comparable devices known in the art.

The integrallymounted bimetallic circuit breakers 34 are entirelyenclosedwithin the recess formed by the inner base wall 28, the outerbase wall 30 and the two basic parts of the device, namely the flangeand the base. An end of each circuit breaker 34 is firmly held inposition by a rivet so positioned in the base that the free end of eachcircuit breaker 34 will make contact during normal operation with arivet connected to a bus strip 24. When a circuit is overloaded, thebimetallic element will heat up and at its breaking point. will bendupward, opening the circuit and cutting off the flow of current.

In some situations, as where a trailer is made of nonconducting materialsuch as Fiberglas or plywood, the grounding pin may be effectivelyconnected to ground by a wire from the mounting screw in one of themounting holes 44, the ground pin being integral with the flange.

Finally, unlike prior art devices, the trailer connector of the presentinvention has only two major parts easily disassembled by removing threescrews and equally easily assembled by replacing those screws. Moreover,the formation of the receiving chamber as a part of the relativelystrong flange rather than as a part of the relatively fragile base addsto the strength mi ht swivel and cause shorts or by ass the circuitbreakers.

hat has been shown and descri ed is a preferred-embodiment of thepresent invention. The scope of the invention, however, is defined inthe following claims.

What we claim is: V 1. In an electrical connector socket for use inenvironments of exposure to weather and rough motion wherein power andcontrol currents are transferred between said socket and a cable plug,the combination of a flange of conducting material having a receivingchamber formed therein, at least a portion of the bottom of said chamberbeing defined by a-conducting segment, a ground pin fixedto saidconducting segment and projecting into said chamber, a detachableinsulatingbase mounted on said flange, a plurality -of conducting pinsmounted on said base and projecting into saidchamber parallel to saidground pin, said insulating base having a recess formed therein, aplurality of circuit breakers disposed in said recess, means connectingone end of each of said circuit brwkers to one of said conducting pins,and terminal connector means connected to the other end of each ofsaidcircuit breakers. 1

2. In an electrical connector socket asdefined in claim 1, thecombination wherein said means connecting one end of each of saidcircuit breakers to one of said conducting pins comprises a plurality ofindividual bus strips, said insulating base having a like plurality ofsecond recesses formed therein,

said bus strips being individually permanently affixed in said secondrecesses.

3. In an electrical connector socket as defined in claim 1, for use witha trailer said flange being adapted for mounting on said trailer, thecombination wherein said insulating base includes spaced concentricwalls formed on the surface thereof adjacent said flange, said walls,said base and said flange defining said recess and enclosing saidcircuit breakers.

4. in an electrical connector socket as defined in claim 1, thecombination which includes a spring-loaded normally closed hinged covermounted on said flange to cover said receiving chamber and a tongueformed on the inner surface of said cover, said tongue being adapted toengage an element inserted in said receiving chamber upon opening ofsaid hinged cover.

5. An electrical connector socket for a trailer comprising two majorelements, a flange'of conducting material and a base of insulatingmaterial for attachment to said flange, said flange having a circularrecess formed in a surface thereof and said'base having a generallymatching recess formed in a surface thereof whereby a closed volume isformed by assembling said flange and said base together, a plurality ofcircuit breakers permanently fixed to said base and disposed in saidclosed volume, a plurality of conducting pins fixed in said base eachsaid pin being electrically connected to one of said circuit breakers,said base having a cylindrical chamber formed therein, said conductingpins being disposed in parallel array in said chamber.

6. In an electrical connector socket for a trailer as defined in claim5, the combination therewith of a segment of conducting materialdisposed at an end of said chamber and electri-

1. In an electrical connector socket for use in environments of exposure to weather and rough motion wherein power and control currents are transferred between said socket and a cable plug, the combination of a flange of conducting material having a receiving chamber formed therein, at least a portion of the bottom of said chamber being defined by a conducting segment, a ground pin fixed to said conducting segment and projecting into said chamber, a detachable insulating base mounted on said flange, a plurality of conducting pins mounted on said base and projecting into said chamber parallel to said ground pin, said insulating base having a recess formed therein, a plurality of circuit breakers disposed in said recess, means connecting one end of each of said circuit breakers to one of said conducting pins, and terminal connector means connected to the other end of each of said circuit breakers.
 2. In an electrical connector socket as defined in claim 1, the combination wherein said means connecting one end of each of said circuit breakers to one of said conducting pins comprises a plurality of individual bus strips, said insulating base having a like plurality of second recesses formed therein, said bus strips being individually permanently affixed in said second recesses.
 3. In an electrical connector socket as defined in claim 1, for use with a trailer said flange being adapted for mounting on said trailer, the combination wherein said insulating base includes spaced concentric walls formed on the surface thereof adjacent said flange, said walls, said base and said flange defining said recess and enclosing said circuit breakers.
 4. In an electrical connector socket as defined in claim 1, the combination which includes a spring-loaded normally closed hinged cover mounted on said flange to cover said receiving chamber and a tongue formed on the inner surfaCe of said cover, said tongue being adapted to engage an element inserted in said receiving chamber upon opening of said hinged cover.
 5. An electrical connector socket for a trailer comprising two major elements, a flange of conducting material and a base of insulating material for attachment to said flange, said flange having a circular recess formed in a surface thereof and said base having a generally matching recess formed in a surface thereof whereby a closed volume is formed by assembling said flange and said base together, a plurality of circuit breakers permanently fixed to said base and disposed in said closed volume, a plurality of conducting pins fixed in said base each said pin being electrically connected to one of said circuit breakers, said base having a cylindrical chamber formed therein, said conducting pins being disposed in parallel array in said chamber.
 6. In an electrical connector socket for a trailer as defined in claim 5, the combination therewith of a segment of conducting material disposed at an end of said chamber and electrically connected to said flange and a ground pin mounted on said segment and extending into said chamber in parallel relationship to said conducting pins. 